Even small problems can cause your air conditioner to stop working completely, so it can sometimes be difficult to narrow down. Electrical issues are the most common cause of functionality problems, but moisture drainage issues can play a part as well.
Blown or Worn Fuses
Your fuses are inexpensive electrical components primarily responsible for protecting more expensive and complex parts from being damaged by electrical problems. For example, if there's an electrical surge, your fuses will blow, preventing the surge from damaging the motor. The only catch is that when the fuses fail, the rest of your air conditioner won't work even if nothing is wrong with any of its other parts. A technician can help locate and safely replace your fuses with ones appropriate for your unit.
As the control panel for your whole HVAC system, your thermostat won't be able to turn your air conditioner on if it has started to fail. If you've already checked its batteries, or if it should run off your home's power, then your thermostat could be experiencing a more serious problem.
A typical thermostat should last you at least ten years, though its lifespan could be shortened if it's subject to any electrical or physical damage. A technician can test your thermostat by checking its systems and bypassing the thermostat to operate your air conditioner. If your air conditioner turns on just fine during this bypass, your thermostat will likely need to be fixed or replaced.
Capacitors provide the surge and steady supply of power needed to run bigger moving parts like your fan motor. A burst of power is needed to get the fan moving from a standstill, and if this power isn't provided, your air conditioner won't run even if the motor is fine. One sign this could be the problem is if you feel room-temperature air coming from your registers, or if you hear a humming noise from the condenser unit but nothing is moving.
While capacitors are a little more expensive than fuses, they can also be swapped out with the help of a technician without requiring any further repairs or part replacements.
Clogged or Broken Condensate System
The condensate system lets moisture drain outside your home as it's pulled from the air during the cooling process. If there's something wrong with this system, such as if the drains are clogged or if a part is broken, your air conditioner may start shutting itself down automatically to protect itself against water damage.
Depending on the cause, your technician may need to replace the affected parts or simply clear the drain clog for you. Since this problem doesn't usually affect or damage any other components, a quick air conditioning repair should get your air conditioner up and running again quickly.